Hsu Jane-Yi, Chen Wei-Teing, Kao Chung-Cheng, Lee Shih Jun, Chang Hung
Division of Thoracic Surgery, Department of Surgery, Armed Forces Kaohsiung General Hospital, Taoyuan.
Chin J Physiol. 2008 Feb 29;51(1):48-53.
Ventilation with higher fraction of inspired oxygen (F(I)O2) is one of the commonly-chosen strategies executed for treatment of hypoxemia during one lung ventilation (OLV) for thoracic surgery. In this study, we investigated the effect of F(I)O2 on pulmonary ventilation-perfusion (VA/Q) distribution during OLV. Six pigs, weighing 27 to 34 kg, were selected for this study. Following by a steady-state period, randomized administrations of F(I)O2 with 0.4, 0.6 and 1.0 were performed for 30 minutes at the right lateral decubitus position during OLV, while hemodynamic data and lung mechanics were simultaneously monitored. The VA/Q distributions of the lung(s) were assessed by the multiple inert gas elimination technique (MIGET). PaO2 at F(I)O2 of 100% was significantly reduced in OLV compared with two-lung ventilation (TLV) (522 +/- 104 vs. 653 +/- 21 mmHg; P < 0.001) at right lateral decubitus position. MIGET algorithms demonstrated a wider VA/Q distribution during OLV at F(I)O2 of 40%, as compared with distribution during TLV at F(I)O2 of 100%, but a bimodal perfusion distribution shifted to lower VA/Q component during OLV at F(I)O2 of 100%. There was an increase of pulmonary shunting in OLV, as compared with TLV at F(I)O2 of 100% (1.94 +/- 2.2% vs. 9.5 +/- 9.7%; P < 0.01). In addition, OLV caused a significant increase in the dispersion of perfusion at F(I)O2 of 100% (0.62 +/- 0.20 vs. 0.44 +/- 0.23; P < 0.01), but ventilation showed no denoting changes (1.06 +/- 0.20 vs. 0.98 +/- 0.35; P > 0.01). During OLV with right lateral decubitus position, there were no significant changes in the pulmonary shunt, the dispersion of perfusion and ventilation at different F(I)O2. OLV resulted in an increase in pulmonary shunting and heterogeneity compared with TLV. Furthermore, the PaO2 decreased during OLV regardless of the postural changes. At different F(I)O2, there were no significant changes in the pulmonary shunt, the dispersion of perfusion and ventilation during OLV with right lateral decubitus posture.
在胸外科单肺通气（OLV）期间，采用较高的吸入氧分数（F（I）O2）进行通气是治疗低氧血症常用的策略之一。在本研究中，我们调查了F（I）O2对OLV期间肺通气-灌注（VA/Q）分布的影响。选择6头体重27至34千克的猪进行本研究。在一个稳定期后，在OLV期间右侧卧位随机给予F（I）O2为0.4、0.6和1.0，持续30分钟，同时监测血流动力学数据和肺力学。通过多惰性气体排除技术（MIGET）评估肺的VA/Q分布。在右侧卧位时，与双肺通气（TLV）相比，OLV时F（I）O2为100%时的动脉血氧分压（PaO2）显著降低（522±104 vs. 653±21 mmHg；P<0.001）。MIGET算法显示，与F（I）O2为100%时TLV期间的分布相比，OLV时F（I）O2为40%时VA/Q分布更宽，但在F（I）O2为100%时OLV期间双峰灌注分布向较低VA/Q成分转移。与F（I）O2为100%时的TLV相比，OLV时肺内分流增加（1.94±2.2% vs. 9.5±9.7%；P<0.01）。此外，OLV导致F（I）O2为100%时灌注离散度显著增加（0.62±0.20 vs. 0.44±0.23；P<0.01），但通气无明显变化（1.06±0.20 vs. 0.98±0.35；P>0.01）。在右侧卧位OLV期间，不同F（I）O2时肺内分流、灌注离散度和通气均无显著变化。与TLV相比，OLV导致肺内分流和异质性增加。此外，无论体位如何改变，OLV期间PaO2均降低。在右侧卧位OLV期间，不同F（I）O2时肺内分流、灌注离散度和通气均无显著变化。
